Peripheral cam actuating a plurality of contact blades

ABSTRACT

A four step cam operates electrical contacts to open and close electrical circuits to four electrical terminals which are spaced from and substantially in alignment with the rotational direction of the cam.

O United States Patent [191 [111 3,858,017 Bertozzi et al. Dec. 31, 1974PERIPHERAL CAM ACTUATING A [56] References Cited PLURALITY OF CONTACTBLADES UNITED STATES PATENTS [76] Inventors: Marcello Bertozzi, No. 47,Via 2,935,591 5/1960 Lee 200/ 153 LB Brighindi; Mario Chioffi, NO 842,938,970 5/1960 Constantine ZOO/38 B via Marittima 1 of Fr in neHOiZ.el' B Italy 3,752,944 8/1973 Cartier et al. 200/38 B [22] Filed:1973 A Primary Examiner-Robert K. Schaefer [21] APPL 420 903 AssistantExaminer-William J. Smith Attorney, Agent, or FirmCharles W. Hoffmann;

Robe t F. Me er; Donald W. H s [30] Foreign Application Priority Data ry an on July 12, 1973 Italy 51427/73 [57 ABSTRACT A four step camoperates electrical contacts to open zoo/153 2 2 43 and close electricalcircuits to four electrical terminals [58] Fie'ld B 153 LB which arespaced from and substantially in alignment 200/38 BA, 27 BA, 27 BB, 6 B,6 BB, 283, 246

with the rotational direction of the cam.

3 Claims, 2 Drawing Figures PAIENIED BEES I ma SHEET 2 OF 2 PERIPHERAL.CAM ACTUATING A PLURALITY OF CONTACT BLADES Generally speaking, thereis provided in the present invention a means for selectively completinga plurality of electrical circuits comprising a rotatable cam having atleast four consecutive steps; at least four electrical terminals carriedby an electrically insulative base in a line, spaced from and in linewith the rotational direction of the cam; a first spring contact bladeaffixed at one end to a first electricalterminal at one end of the line,at least one electrical contact carried at a free end of the blade, anda cam follower carried between the fixed and free ends and responsive tothe cam; a second spring contact blade affixed at one end to a secondelectrical terminal disposed next to the first electrical terminal;means carried by the base engaging a free end of the second springcontact blade to limit its travel; at least one electrical contactcarried by the second spring contact blade between the fixed and freeends; a first stationary electrical contact carried by a thirdelectrical terminal disposed next to the second electrical terminal andcooperating with the electrical contact carried by the second springcontact blade; and a second stationary contact carried by a fourthelectrical terminal disposed at another end of the line and cooperatingwith the electrical contact carried by the first spring contact blade.

The present invention concerns an improvement in the arrangement ofcontacts and is particularly adoptable to cam driven electro-mechanicaltimers.

The timers commonly used for example, in electrical home appliances,such as clothes washers, dish washers and the like, include at least asmall base or support of insulating material on which are mounted fixedor mobile contacts (contact springs) usually connected to currentcarriers in which the mobile contacts perform the electricalcommutations to the fixed contacts under a mechanical drive supplied byrotating cams having a pre-fixed profile as a function of the desiredcommutation sequence.

Normally, the contact arrangements in timers of the described commonlyused type, are comprised of simple opening and closing contacts and/orexchange contacts.

The principal feature of the present invention is that of furnishing animproved contact arrangement for electro-mechanical contacts of theaforementioned type which enables the attainment of an additionalcontact closing (.and opening) in contrast to the well known type ofarrangement.

The present invention will now be described with reference to itscurrently presented design as an illustrative and not limiting example,based on the attached drawings in which:

FIG. 1 shows schematically the structure of the contact arrangementaccording to the present invention.

FIG. 2 shows a variation of the arrangement shown in FIG. 1.

With reference to the drawings and particularly to FIG. -I, there isprovided a base 1 of insulating material, sufficiently sturdy from amechanical standpoint to maintain in place, the anchorings or electricalterminals 2, 3, 4, 5 spaced from cam 18 and substantially aligneddirectionally with its rotation.

Affixed to terminal 2, is a small metallic square 6 on which is carriedan electrical contact pellet 7. To terminal 5 is affixed a first contactspring blade 8 arranged to exert force in the direction of the arrow Fl, on the free end of which are carried electrical contact pellets 9,l0. Affixed to terminal 4, is a second contact spring blade 11, arrangedto exert force in the direction of the arrow F 2 and having a firstelectrical contact pellet 12 disposed in its center position withrespect to its length, and a second electrical contact pellet 13 at itsfree end position. The terminal end 14 of the spring 11 extends untilcoming into contact with the junction 15 in the small insulation base 1to provide a means engaging the blade to limit its travel. Finallyelectrical contact pellet 16 is affixed to terminal 3.

The contact spring 8 is furnished, approximately in center position,with a tooth 17, the free end of which is arranged to engage the profileof rotating cam 18, shown only in part.

The cam 18 has four successive steps B, A, C, D, each defining fourcircumferences 20, 19, 21, and 22.

During the operation of the structure shown in FIG. 1, when the end ofthe tooth 17, engages zone A (neutral zone of the cam 18), the variouscontacts are found in the positions indicated and all circuits are open.When tooth 17 engages zone B (lower) of the cam 18, under the pre-loadaction of the spring 8 indicated by the arrow F l, the pellets 7 and 9will enter into contact, closing the circuit between terminals 2 and 5.When tooth 17 engages zone C of the cam 18 (first upper) there will becontact between the pellets 10 and 13 with a pressure determined by thepre-load of the spring 11 indicated by the arrow F 2 and a circuitbetween terminals 4 and 5 will be closed. Finally when tooth 17 engageszone D of the cam (second upper) besides engaging pellets 10 and 13,there will also be an engagement of pellets 12 and 16 and thereforethere will be a closing of the circuit between terminal 5 and terminals3 and 4.

In FIG. 2, is shown a variation of the FIG. 1 concept for the case inwhich a circuit closing between terminals 4 and 5 is not necessary ordesired. With this object in mind, a spacer or insert 23 is mounted onspring 11 which, in correspondence with the rising of the tooth 17controlled by zone D of the cam 18, controls the closing of contacts 12and 16 and therefore the circuit between terminals 3 and 4. Theremainder of parts shown in FIG. 2 are identical to those in FIG. 1 andcarry the same reference numbers.

What is claimed is:

1. Means selectively activating a plurality of electrical circuitscomprising:

a. a rotatable cam, said cam having at least four successive steps,

b. at least four electrical terminals carried by an electricallyinsulative base in a line, spaced from and in alignment with therotational direction of said cam,

c. a first spring contact blade affixed at one end to a first electricalterminal at an end of said line, at least one electrical contact carriedat a free end of said blade, and a cam follower carried between saidfixed and free ends, said cam follower responsive to said cam,

d. a second spring contact blade affixed at one end to a secondelectrical terminal disposed next to said first electrical terminal,

e. means carried by said base engaging a free end of of said line andcooperating with said electrical contact carried by said first springcontact blade.

2. Means according to claim 1 wherein spacer means is carried on saidsecond spring contact blade, said 5 spacer means engaging said firstspring contact blade.

3. Means according to claim 1 wherein there is another electricalcontact carried at said free end of said second spring contact bladecooperating with another electrical contact carried at said free end ofsaid first spring contact blade.

1. Means selectively activating a plurality of electrical circuitscomprising: a. a rotatable cam, said cam having at least four successivesteps, b. at least four electrical terminals carried by an electricallyinsulative base in a line, spaced from and in alignment with therotational direction of said cam, c. a first spring contact bladeaffixed at one end to a first electrical terminal at an end of saidline, at least one electrical contact carried at a free end of saidblade, and a cam follower carried between said fixed and free ends, saidcam follower responsive to said cam, d. a second spring contact bladeaffixed at one end to a second electrical terminal disposed next to saidfirst electrical terminal, e. means carried by said base engaging a freeend of said second spring contact blade to limit its travel, f. at leastone electrical contact carried by said second spring contact bladebetween said fixed and free ends, g. a first stationary electricalcontact carried by a third electrical terminal disposed next to saidsecond electrical terminal cooperating with said electrical contactcarried by said second spring contact blade, and h. a second stationaryelectrical contact carried by a fourth electrical terminal disposed atanother end of said line and cooperating with said eLectrical contactcarried by said first spring contact blade.
 2. Means according to claim1 wherein spacer means is carried on said second spring contact blade,said spacer means engaging said first spring contact blade.
 3. Meansaccording to claim 1 wherein there is another electrical contact carriedat said free end of said second spring contact blade cooperating withanother electrical contact carried at said free end of said first springcontact blade.